A category of musical instruments known as keyboard percussion instruments includes marimbas, vibraphones, xylophones and glockenspiels. Referring to FIGS. 1 and 2, a keyboard percussion instrument 10 generally includes keys known as tone bars 14 that are supported on support rails 22 such that the tone bars 14 are allowed to ring freely when struck by a mallet (not shown). The tone bars 14 and support rails 22 may form a tone bar rail assembly (sometimes referred to as the “harp”). The keyboard percussion instrument may also include a frame 20 that supports the tone bar rail assembly. The keyboard percussion instrument 10 may further include resonators 15 mounted below the tone bars 14.
The keyboard percussion instrument 10 may also include a dampening system including a damper 30 to dampen the tone bars 14 and control the ringing. The dampening system may include a pedal 34 for user actuation of the dampening. Examples of such keyboard percussion instruments are described in greater detail in U.S. Pat. Nos. 6,245,978 and 5,977,465 and in U.S. Patent Application Publication No. 2008/0105105, all of which are fully incorporated herein by reference.
The damper pedal 34 may operate similarly to the sustain pedal of a piano. When the damper pedal is in a neutral position, one or more damper pads are in contact with the tone bars. By depressing the damper pedal, the instrumentalist disengages the damper pad(s) from the tone bars, allowing them to decay naturally unless the damper pedal is released and the damper pad(s) re-engage. One example of a dampening system for use with a keyboard percussion instrument is described in greater detail in U.S. Provisional Patent Application Ser. No. 61/111,161 and U.S. patent application Ser. No. 12/612,050, published as U.S. Patent Application Publication No. 2010/0107852, which are fully incorporated herein by reference.
The vibraphone usually includes an apparatus to provide vibrato effects. One such apparatus includes an array of disks, mounted on an axle inside the tops of the resonating tubes. These disks are spun by an electric motor and alternately partially block, then partially open the tops of the tubes as the motor spins, producing the traditional steady-state vibrato sound. In these traditional vibraphones, the speed of the vibrato may be controlled by adjusting the rate of the electric motor controlling the rotational speed of the discs, but with almost no possibility for the player to control the vibrato speed to match the underlying rhythm of the music or to adjust the speed on an instantaneous basis to match the expressive needs of an individual note, chord or moment in the music.
More recently, alternative methods for producing the vibrato effect have been introduced which allow the instrumentalist to control the vibrato volume modulation effect with manual controls rather than adjusting the speed of a motor. Examples of such methods are described in greater detail in U.S. Patent Application Publication No. 2008/0314227, now U.S. Pat. No. 7,732,691, which is fully incorporated herein by reference. This human powered, manually controlled vibrato feature may be adjusted during the performance on a measure by measure, beat by beat basis.
Providing adequate control over both the dampening and vibrato effects of a vibraphone without interfering with the instrumentalist's hand and finger technique presents unique challenges. Providing the desired level of manual control over both of these features independently is particularly difficult because the hands are usually carrying multiple mallets when playing the vibraphone, for example.